Specifications: The T-nut is rust resistant with carbon steel material and nickel-plated surface treatment. This 20 series T-nut is a special fastener for European standard profiles (T-slots), widely used in CNC routers, robotics projects, industrial frame structures, and similar applications. It is easy to install; simply insert the nut head into the groove and rotate 90 degrees clockwise for automatic positioning and locking. Item Name: T Nut Material: Carbon Steel Surface Treatment: Nickel-plated Quantity: 50 Pieces Model: M3, M4, M5 Features: Easy to Install, Nickel-plated, T-Type Nut Size: 1.03cm x 0.6cm x 0.5cm / 0.41" x 0.24" x 0.2" (Approx.) Notes: Due to differences in lighting and screen settings, the item color may vary slightly from the images. Please allow slight dimensional differences due to manual measurement. Package Includes: 50 x T Nuts